Twenty-three years ago the Chinese People's Liberation Army violently cleared Beijing's Tiananmen Square of protesters. The demonstration called for democracy and widespread political reform. The protests began in April of 1989, gaining support as initial government reactions included concessions. Martial law was declared on May 20, troops were mobilized and pushed into Tiananmen Square, crushing some protesters and firing on many others. The exact number killed may never be known, but estimates range from several hundred to several thousand.